Chiral Structures from Achiral Micellar Lyotropic Liquid Crystals under Capillary Confinement
Clarissa F Dietrich1, Per Rudquist2, Kristin Lorenz1
1Institute of Physical Chemistry, University of Stuttgart , Pfaffenwaldring 55, 70569 Stuttgart, Germany.
Langmuir : the ACS Journal of Surfaces and Colloids
|May 17, 2017
Summary
Spontaneous reflection symmetry breaking was observed in a nonchromonic liquid crystal within cylindrical capillaries. This study reveals new configurations, including a double-helix structure, expanding our understanding of liquid crystal behavior.
Area of Science:
- Soft Matter Physics
- Materials Science
- Liquid Crystal Physics
Background:
- Spontaneous reflection symmetry breaking was previously observed in achiral chromonic liquid crystals within cylindrical capillaries.
- This phenomenon was attributed to the unusually small twist elastic modulus in chromonic liquid crystals.
Purpose of the Study:
- To experimentally observe and characterize reflection symmetry breaking in a classical, achiral, nonchromonic lyotropic liquid crystal.
- To investigate the formation of new configurations and compare them with those found in chromonic systems.
Main Methods:
- Confining a lyotropic liquid crystal (nematic phase of disklike micelles) in cylindrical capillaries with homeotropic anchoring.
- Observing and analyzing the resulting liquid crystal configurations using microscopy and theoretical analysis.
Main Results:
- Observed the twisted-escaped radial (TER) configuration, previously seen in chromonic liquid crystals.
- Discovered a novel nonplanar twisted polar (TP) configuration characterized by a double helix of twist disclinations along the capillary axis.
- Identified a transverse twist between disclination lines with the same handedness as the axial twist.
Conclusions:
- Reflection symmetry breaking occurs in nonchromonic lyotropic liquid crystals under similar confinement conditions.
- The chiral TER configuration can be stabilized by point defects.
- The study provides insights into the fundamental mechanisms of symmetry breaking in confined liquid crystals.
Related Concept Videos
01:30Micelles
44
Micelle formation is an intricate process that hinges on the properties of amphiphilic or amphipathic molecules and the conditions of the system in which they are found. Amphiphilic molecules, which have both hydrophilic (water-attracting) and hydrophobic (water-repelling) parts, play a critical role in this process.In aqueous environments, these molecules arrange themselves such that their hydrophilic heads are turned towards the water phase, while their hydrophobic tails are oriented away...
44
02:30Chirality in Nature
17.4K
Chirality is the most intriguing yet essential facet of nature, governing life’s biochemical processes and precision. It can be observed from a snail shell pattern in a macroscopic world to an amino acid, the minutest building block of life. Most of the snails around the world have right-coiled shells because of the intrinsic chirality in their genes. All the amino acids present in the human body exist in an enantiomerically pure state, except for glycine - the sole achiral amino acid.
17.4K
02:25Molecules with Multiple Chiral Centers
15.5K
Molecules that possess multiple chiral centers can afford a large number of stereoisomers. For instance, while some molecules like 2-butanol have one chiral center, defined as a tetrahedral carbon atom with four different substituents attached, several molecules like butane-2,3-diol have multiple chiral centers. A simple formula to predict the number of stereoisomers possible for a molecule with n chiral centers is 2n. However, there can be a lower number where some of the stereoisomers are...
15.5K
02:25Chirality
30.7K
Chirality is a term that describes the lack of mirror symmetry in an object. In other words, chiral objects cannot be superposed on their mirror images. For example, our feet are chiral, as the mirror image of the left foot, the right foot, cannot be superposed on the left foot.
Chiral objects exhibit a sense of handedness when they interact with another chiral object. For example, our left foot can only fit in the left shoe and not in the right shoe. Achiral objects — objects that have...
Chiral objects exhibit a sense of handedness when they interact with another chiral object. For example, our left foot can only fit in the left shoe and not in the right shoe. Achiral objects — objects that have...
30.7K
02:05Prochirality
5.2K
The concept of prochirality leads to the nomenclature of the individual faces of a molecule and plays a crucial role in the enantioselective reaction. It is a concept where two or more achiral molecules react to produce chiral products. A typical process is the reaction of an achiral ketone to generate a chiral alcohol. Here, the achiral reactant reacts with an achiral reducing agent, sodium borohydride, to generate an equimolar mixture of the chiral enantiomers of the product. For example, an...
5.2K
02:33Stereoisomerism of Cyclic Compounds
11.4K
In this lesson, we delve into the role of ring conformation and its stability, which determines the spatial arrangement and, consequently, the molecular symmetry and stereoisomerism of cyclic compounds. 1,2-Dimethylcyclohexane is used as a case study to evaluate the possible number of stereoisomers. Here, given the multiple (n = 2) chiral centers, there are 2n = 4 possible configurations that lack a plane of symmetry, as the ring skeleton exists in a non-planar chair conformation. In addition,...
11.4K